Cooling Fan Circuit Breaker

[Notifier]

I was going to switch out the 35amp cooling fan breaker with a new 40amp breaker I received in the relay update kit and ran into a little problem. My old breaker resembles the one on the left (this is actually a 25amp breaker but the 35amp looks exactly the same), the new breaker is the one on the right. The problem is, I have 4 wires going onto all 4 quick disconnects on the old breaker, the new one only has 2 terminals. So I guess my question is, is this normal or just something odd about my car in particular? And without modifying the original wiring, is there any way to make this work?

breakers.jpg

[David T]

I was going to switch out the 35amp cooling fan breaker with a new 40amp breaker I received in the relay update kit and ran into a little problem. My old breaker resembles the one on the left (this is actually a 25amp breaker but the 35amp looks exactly the same), the new breaker is the one on the right. The problem is, I have 4 wires going onto all 4 quick disconnects on the old breaker, the new one only has 2 terminals. So I guess my question is, is this normal or just something odd about my car in particular? And without modifying the original wiring, is there any way to make this work?

breakers.jpg

Contact the vender you purchased the kit from. He needs to get you clips that will allow you to hook 2 wires to each terminal. The cooling fan circuit breaker does have 4 wires connected to it, 2 to each side. Try to hook them up to the correct side, it matters.

[Bitsyncmaster]

I think the cooling fan breaker (40 amp) only has two wires. Mine is removed because I have fuses in the fan fail so my comment is from memory. The blower motor breaker (30 amp) does have the 4 wires.

[DMCMW Dave]

I think the cooling fan breaker (40 amp) only has two wires. Mine is removed because I have fuses in the fan fail so my comment is from memory. The blower motor breaker (30 amp) does have the 4 wires.

Correct. The heater blower has 4 wires (power, speed 3, speed 4, and the starter recall feed wire). The cooling fan breaker (the larger of the two) has two wires.

For a better connection (involves modifying factory wiring - purists look away) you can cut the terminals off the wiring and change them to properly crimped ring lugs, and use the studs/nuts on the breaker. It's a much more solid connection and will run cooler, and be more reliable for the long haul.

As David T alluded to - the breakers are typically marked "BATT" and "LOAD" or something similar. The "BATT terminal should have the "hot" wire on it, and the load should be on the other terminal. Although the starter recall wire (The 4th wire on the blower breaker) is paired with the source and is therefore not protected. It never was anyway.

[David T]

Correct. The heater blower has 4 wires (power, speed 3, speed 4, and the starter recall feed wire). The cooling fan breaker (the larger of the two) has two wires.

For a better connection (involves modifying factory wiring - purists look away) you can cut the terminals off the wiring and change them to properly crimped ring lugs, and use the studs/nuts on the breaker. It's a much more solid connection and will run cooler, and be more reliable for the long haul.

As David T alluded to - the breakers are typically marked "BATT" and "LOAD" or something similar. The "BATT terminal should have the "hot" wire on it, and the load should be on the other terminal. Although the starter recall wire (The 4th wire on the blower breaker) is paired with the source and is therefore not protected. It never was anyway.

Sorry for any confusion, Dave S got it right, the one with 4 wires is the heater fan, the one with 2 wires is for the cooling fans. Besides getting the power and load sides correct you need to get the right size in the right place. The one on the left (as you are looking at the 2 circuit breakers) is the 40 amp cooling fans with 2 wires and the one on the right is the heater fan with 4 wires and should be 30 amps. I had my circuit breakers in the wrong spots, reversed, (it had no effect except to misidentify them). I agree ring terminals will handle higher currents better if you don't mind cutting up your wiring harness. The whole wiring of the car could be better done. For instance there is no fusible link to protect anything and there is a lot of unprotected wiring. The circuit breaker for the door lock module is a joke, it is WAY too big and should not automatically reset. There should be a separate, dedicated grounding system and there should be a V+ and a V- bus from the front to the rear. That is how Lotus eventually did it in later years. BTW if you think the wiring is OK then don't try swapping relays, stick the wrong one in the wrong place and you don't blow fuses, you melt the wiring harness!!!!!!